Method and apparatus for producing headers



Dec. 8, 1925- A. COTTON METHOD AND APPARATUS FOR PRODUCING HEADERS Filed March 27, 1924 IN vEA/TOE fi/frea (0770/7. I

Patented Dec. 8, 1925.

UNITED STATES PATENT OFFICE.

ALFRED COTTON, OF ST. LOUIS, IllISSOURI, ASSIGNOR TO HEIIIE BOILER COMPANY; OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

METHOD AND APPARATUS FOR PRODUCING HEADERS.

Application filed March 27, 1924. Serial No. 702,279.

To all whom it may concern:

Be it known that I, ALFRED COTTON, a citizen of the United States, residing at St. Louis, Missouri, have invented a certain new and useful Improvement in Methods and Apparatus for Producing Headers, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to headers of the kind that consist of a hollow member constructcd from a welded or drawn tube of circular or oval shape in cross section that is deformed by pressure applied externally to the front and rear sides and to the lateral sides of the tube in such a way as to produce a header having alternately-arranged valleys and ridges on each of its lateral sides and alternately-arranged valleys and ridges on its front and rear sides. I

In my pending application for Patent Serial No. 655,666, filed August 4, 1923, I have disclosed a machine for producing such a header by deforming a tube by a rolling operation and simultaneously forming flat faces on the front and rear sides of the tube that constitute seats for the handhole covers of the header and seats for the tubes to which the header is connected, said machine comprising four right-angularly-disposed rolls that act on the exterior of the tube and deform it progressively, and a collapsible mandrel for internally supporting the portions of the front and rear sides of the tube that are flattened to form hand hole cover seats and tube seats.

The main object of my present invention is to provide a method of producing a header of the general type referred to which makes it possible to use sand or other suitable grandular material to internally support a tube that is being deformed progressively by external rolls, two of which are provided with pressing portions that form sharpangled, flat-faced indentations in the front and rear sides of the tube, that constitute seats for the hand hole covers of the header and seats for the ends of the tubes to which the header is connected.

Another object is to provide a practicable apparatus or machine for practicing my method.

In a header of the kind above referred to the cross sectional area of the header is smaller at all points along its length than the cross-sectional area of the tube from which it is formed, owing to the fact that the lateral sides of the header are made up of opposed inwardly-pressed portions and opposed outwardly-bulged portions, and the front and rear sides of the header are also made up of inwardly-pressed portions and outwardly-bulged portions that have flatfaced indentations produced'by pressing portions on the front and rear rolls. Consequently, in manufacturing such a header it is not feasible to completely .fill a tube with sand or the like and then deform the tube progressively by passing it between two pairs of right-angular-ly-disposed rolls that press opposed portions of the tube inwardly, because the sand, which is virtually incompressible, would offer so great a resistance to the inward pressure of the rolls that the bulged portions of the tube would not be symmetrical and the pressing portions on the front and rear rolls would be apt to shear through the tube, instead of simply pressing sharp-angled, flat faces in the tube.

I have discovered, however, that granular material such as sand can be used successfully for internally supporting a tube that is being deformed progressively by rolls, some of which are provided with pressing portions that form flat seat faces in the tube, if the granular material is arranged in the tube in such a manner that it is capable of flowing longitudinally of the tube away from the portion of the tube be ing acted on by the deforming rolls, but will ofler sufficientlateral resistance to the inward pressure exerted on the tube by the rolls, to cause the pressing portions on the front and rear rolls to form fiat-faced, sharp-angled indentations in the tube without subjecting the tube to abnormal strains.

A comparatively small resistance to longitudinal flow of the granular material in the tube is sufficient to cause said granular material to offer an enormous resistance laterally. Accordingly, I propose to internally support a tube that is being deformed progressively by rolls, some of which are provided with flat-faced pressing portions, by filling the tube with sand-or other suitable granular material for some distance above the point where the rolls are acting on the tube, so as to virtually form a head of sand in the tube that impose a load on the sand which fills the portion of the tube being" acted upon bythe rolls,and maintaining this head constant, or practically so, while the tube is being deformed and fed through the rolls. hen the rolls are revolving the column of sand or other granular material in the tube thatextends upwardly above the portion of the tube being acted upon by the rolls will flow upwardly longitudinally of the tube and relative to the tube as the tube is deformed. Consequently, the friction of said column ofsand against the sides of the tube, as well as theweight of said column, is used to resist longitudinal flow of the sand that fills the portion of the tube which is being engaged by the rolls. The greater the area of contact between the sand and the tube, the greater is the friction. Thegreater the height of the sand above a given point, the greater is the pressure of the said against the tube at that point, and this increases the friction between the sand and the tube.-

Since with a cylindrical or oval tube such as is used in practicing my method the area of contact varies as the length of the tube, the friction varies as the height of the sand above the rolls. After the requisite volume of the column of sand in the tube has been ascertained, it is a simple mat-ter to maintain said column constant, and when the thickness r of the tube used to form the header is tube or, the material of which it is construct-.

ed is changed, the column of sand in the tube can modified to satisfy the changedconditions. i r f, i

Various means canbe used for maintain-- ing a column of granular material in the tube of suilicient volume to insure symmetrical bulged portions on the tube and to eliminate the possibility of the pressing portions on the front and rear rolls cutting through. the parts of the tube in which the flat seat faces are being formed, but the simplest way of accomplishing this is to fill the tube with said or other suitable granular material up to a certain approximate point above the zone of the tube on which the rolls first act and then feed additional sand into the tube as the deforming operation proceeds, at such a rate as to keep the height of the column of sand above the rolls uniform, or substantially uniform. V

Figure 1 of the drawings, is a vertical transverse sectional view of one form of apparatus that can be used for practicing my method; and

Figure 2"is a perspective view of a header produced by said apparatus.

Referring to the drawings, 00 designates a metal tube of oval or circular shape in cross section that is adapted to be fed between two pairs of rolls arranged at right angles to each other and of such shape that they will convert said tube into a header of the kind shown in Figure 2 which has lateral sides, each'of which is made up of a series of valleys 1 arranged between a series of ridges or outwardly-bulged portions 2 and front and rear sides, each of which is made up of a series of bulged portions 3 arranged in alternate relation with a series of valleys a, the valleys 4. in the front and rear sides of the header extending transversely of same and being of reater length than the width of the bulged portions 3 on the front and rear sides of the header. indentations 5 and 6 are formed in the front and rear sides of the tube during the deforming operation so as to form sharp-angled, flat-faced seats for handle hole covers and for the tubes to which the header is to be connected, it being understood that the fiat-faced indentations on the rear side of the header are adapted to have holes cut in same to receive said tubes, and that the flat-faced indentations on the front side of the header are adapted to have hand holes formed in same. Obviously, the shape and area of the indentations 5 and 6 are immaterial. In the header herein shown the identations 5 and 6 above referred to are disposed at a slight angle to the vertical and are produced by pressing portions 5 and 6 on the front roll A and rear roll B of the machine. I have not illustrated the side rolls that act on the sides of the tube, as my present invention relates to a novel method of internally supporting the portion of the tube acted on by the flatfaced pressing portions of the front and rear rolls, it being unnecessary to internally support the portions of thetube acted upon by the side rolls. Suffice it to say that the machine or apparatus in which the tube a? is deformed comprises one pair of rolls composed of a front roll )1 and a rear roll 13, each of which is provided with flat-faced pressing portions 5* and 6, and a second set of side rolls arranged at right angles to the front and rear rolls and of the construction shown in my pending application previously referred to. Each of the various rolls above referred to is mounted on a carriage C that can, be moved towards and away from an openspace at the center of the machine in which the tube a2 is arranged vertically, and means is provided for rotating said rolls after they have been moved into engagement with the tube so as to progressively deform said tube and feed it downwardly between said rolls, the tube being maintained in an upright position by an annular guide D. as shown in Figure 1.

The tubes is closed at its lower end, as shown in Figure 1, so that it can be partly filled with sand or other suitable granular material E that is used to internally support the portions of the tube acted upon by the pressing portions 5 and 6 on the front and rear rolls, and thus cause said pressing portion to form sharp-angled, flat seat faces 5 and 6 in the front and rear sides of the tube. After the tube 00 has been arranged in an upright position between the rolls of the machine, sand or other granular material E is allowed to flow into said tube from a spout 7 that projects downwardly into the tube from a sand hopper 8. The sand is allowed to flow from the spout 7 until it stops, owing to the sand assuming its natural angle of repose from the lower end of said spout. The rolls of the machine are-then moved inwardly into engagement with the tube at, as shown in Figure l, and thereafter said rolls are set in operation so as to press opposed portions of said tube inwardly and feed said tube downwardly, as described in my pending application previously referred to. As the tube :0 passes downwardly more sand flows into same from the spout 7, thereby maintaining a practically constant head or column of sand in the tube above the ti l point at which the rolls are acting on the tube. In order that the column of sand in the portion of the tube above the zone of the tube on which the rolls are acting may be varied, the hopper 8 from which the spout 7 leads is mounted in such a way that it can be raised and lowered with respect to the rolls of the machine, the hopper of the machine herein shown being mounted on brackets 9 that are sustained by co-operating elements 10 adjustably mounted on uprights 11. In an apparatus of the kind above described sand or the like is fed into the tube :6 automatically and is automatically maintained at such a height with relation to the rolls that the sand will accommodate itself to the changing shape of the tube as it becomes a header, but without liability of producing unsymmertical, bulged portions on the tube or causing the pressing portions on the front and rear rolls to shear through the tube.

While I have herein illustrated my method as being carried outin an apparatus in which the feeding of the sand or other granular material into the tube re is auton'iatically controlled by using the angle of repose of the sand at the upper end portion of the column to cut off the escape of sand from the supply spout 7, i wish it to be understood that my bread idea contemplates using any suitable means for fe 'ng sand or other granular material into the tube that is being deformed and for automatically controlling the feed of said sand in such a way as to create and maintain a colun'msand or the like in the tube, that is ree to flow upwardly longitudinally of the tube when the deforming rolls are acting on the tube, but which offers sufficient lateral resistance to the inward pressure exerted on the tube by the rolls to insure the, pressing portions on the front and rear rolls forming fiat-faced, sharp-angled indentations in the tube that will form satisfactory seats for the hand hole covers of the headed and the ends of the boiler tubes to which the header is connected.

lit is often desired to cur-r3 the deformation of the tube to a point so near its upper end that there would not be a suliicient head of sand above the rolls. In other words, it is often necessary to continue the formation of the tube and handhole seats in the tube to such a point towards the upper end of the tube, that the upper end would be fed downward toward the rolls until it was so much below the lower end of the spout 'i that the sand would escape from said spout. In such instances it is necessary to connect a temporary extension to the upper end of the tube a. This can be accomplished easily by connecting a tubular member to the upper end of the tubeby clamps, spotwelding. etc, or said tubular member may be simply telescoped inside or outsiee of the tube At the completion of the deforming operation said temporary ei-zten sion is removed from the header.

Having thus described my invention, what 1 claim as new and desire to secure by Letters Patent is:

1. A. method of producing a header, which consists of progressively deforn'iing a tube by rolls that press opposed portions of the tube inwardly and simultaneously form seat faces in the tube, and internally support ing the tube during the deforu'iing opera tion by a column of granular material. in the tube that is permitted to flow freely longitudinally of the tube but which imposes a sufficient load on the granular mate 'ial in the Zone of the deforming rolls to insure the formation of' seat faces on the tube that are sharp-angled and flat.

2. A method of producing a header, comprising deforming a tube progressively by external pressure exerted on the tube by rolls which form valleys and ridges in opposed portions of the tube and also form indentations in said opposed portions, internally supporting the tube during the deforming operation by a column of granular material in the tube that completely fills the zone of the tube acted upon by said rolls and the adjacent portion of said tube, and which is permitted to flow freely longitudinally of the tube, and maintaining said column practically constant as the deforming operation proceeds, thereby causing the rolls to act uniformly on all portions of the tube and without liability of shearing the tube at the points where the indentations are formed in same.

ill)

A method of producing a header, coinprising detorn'iing a tube progressively by means 0% rolls that press opposed portions of the tube inwardly and simultaneously form indentations in the tube, filling the tube with granular inater'al to a certain height above the zone on which the rolls are acting so as to form a column of granular material in the tube that otters sutficient iateral resistance to the inward pressure of the rolls to insure the formation of sharpangled, fiat-faced indentations, and feeding additional granular material into the tube as the de'lori'ning operation proceeds so as to maintain said column practically constant.

a. A method of producing a header, comprising feeding a tube between opposed rolls, causing said rolls to press opposed portions of the tube inwardly and also form fiat-faced indentations in the tube, internally supporting the tube during the deforming operation by a colun'in of granular material that is permitted to flow freely longitudinally of the tube away from the Zone of the tube on which the rolls are acting, and maintaining said column practically constant during the deforming o- 'jeration, thereby maintaining a practically uniform load on the granular material that fills the portion of the tube on which the deforming rolls are acting.

5. A method of producing a header, com prising deforming a tube progressively by rolls that form inwardly-pressed portions and outwardly-bulged portions in the tube that contain indentations which are used to form seats for hand hole covers and boiler tubes, and internally supporting the tube during the deforming operation by a mass of granular material in the tube that is free to flow longitudinally of the tube in one direction and which exerts a practically uniform load on the granular material which fills the zone of the tube on which the rolls are acting.

6. A method of producing a header, comprising deforming a tube progressively by rolls that form inwardly-pressed portions and outwardly-bulged portions in the tube that contain flat-faced indentations that are used as seats for the hand hole covers of the header and the boiler tubes to which the header is connected, internally supporting the portion of the tube being acted upon by said rolls by a mass of granular material that completely fills the Zone of the tube in proximity to said rolls, and causing said granular material to offer a practically uniform lateral resistance to the pressure of the rolls as the deforming operation proceeds.

7 A method of producing a header, comprising arranging a tube in an upright position between rolls, causing said rolls to act on the tube in such a way as to feed the tube downwardly and simultaneously form inwardly-pressed portions and outv-rardlybulged portions in the tube that contain fiatfaced indentations, filling the tube with granular material prior to the beginning of the deforming operation up to such a height above the Zone of the rolls as to create a column of granular material in the tube that offers the requisite lateral resistance to the inward pressure of the rolls to insure uniform deformation of the tube, and maintaining the height of the said column with respect to the rolls practically constant during the deforming operation by feeding additional granular material into the tube as the tube passes downwardly between the rolls.

An apparatus for producing a header, comprising opposed rolls between which a tube is adapted to be arranged, said rolls being of such shape that they will press opposed portions of the tube inwardly and also form fiat-faced indentations in the tube as the tube travels lengthwise between the rolls, and means for causing the tube to be internally supported during the deforming operation by a mass of granular material that is permitted to flow relatively to the tube in one direction and which exerts a substantially uniform lateral resistance to the inward pressure exerted on the tube by the rolls.

9. An apparatus for producing a header, comprising a pair of rolls between which a tube is adapted to be arranged and provided with co-operating port1ons that deform the tube progressively, feed it lengthwise between the roll and form flat-faced indentations in the tube, and means for introducing granular material into the tube at such a rate as the deforming operation proceeds as to maintain in the tube a column of granular material that offers a substantially uniform lateral resistance to the inward pressure exerted on the tube by the rolls.

10. An apparatus for producing a header, comprising opposed rolls adapted to have a tube arranged in a vertical position between the same and provided with co-ope ating portions that deform the tube progressively, feed it downwardly between the rolls and also form fiat-faced indentations in opposed portions of the tube, a hopper arranged above said rolls for holding granular material, and a spout leading from said hopper and projecting downwardly into said tube fo automatically supplying granular material to the tube, for the purpose described.

11. An apparatus for producing a header, comprising opposed rolls adapted to have a tube arranged in a vertical position between the same and provided with co-operating portions that deform the tube progressively,

feed it downwardly between the rolls and also form flat-faced indentations in opposed portions of the tube, a hopper arranged above said rolls for holding granular ma- 5 terial, a spout leading from said hopper and projecting downwardly into said tube itor automatically supplying'granular material to the tube, for the purpose described, and means for enabling the discharge end of said spout to be raised and lowered with 1 respect to the rolls, for the purpose described.

ALFRED COTTON. 

